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Comment by imaginenore | Hacker News Reader

Microsoft demoed 1ms touchscreen lag in 2012.

Most modern touchscreens still have 100ms lag.

https://www.youtube.com/watch?v=vOvQCPLkPt4

The creators of the drawing app "Colors!" for 3DS and iOS also tested their app's latency across a wide range of devices, and they achieved a 9ms latency in 2004's Nintendo DS:

http://www.collectingsmiles.com/news/measuring-latency-in-co...

  Nintendo 3DS – 23 ms
  PlayStation Vita – 49 ms
  Surface Pro – 100 ms
  iPhone 5 – 81 ms
  Galaxy Note – 71 ms
  Galaxy S3 – 104 ms & Nexus 10 – 99 ms
  Galaxy Note 2 – 132 ms
  Wii U GamePad – 53 ms
  Nintendo DS – 9 ms

Nice video! It really shows the perceptual difference well.

However, I'm not sure it's fair to call it a "touchscreen" when it's most likely a touchpad input surface aligned with an overhead projector. It's impossible to say from the video how feasible it would be to achieve the same performance with an actual touchscreen, let alone a high-resolution mobile device. But I'm looking forward to it. :)

I was under the impression that that setup was something including a camera or something, and not an actual touchscreen.

Yeah, though maybe you could do it with FTIR instead of capacitive, so you wouldn't need external cameras.

This lag is in the software stack (mostly in UI graphics). Not in hardware.

Remember Androids ~>200ms sound lag?

What I've read is most of the lag in the more optimized touchscreen stacks (read=iOS) is due to filtering and smoothing, which takes a few samples to do. The worse stacks (early android) had poor drivers and a lot of layers of abstraction, or worse, Java (maybe this is what you mean when you say "UI Graphics", but the raw numbers we're talking about here are on a far lower layer than scrolling in lists).

Graphics rendering lag is at worst 2 frames of video (double-buffering).

Definitely not. Most of mobile software strives to run at 60fps. That's just 16.7ms.

display animation at 60fps and react to a hardware input through layers and layers of software abstraction are two different things.

Run of the mill 3M controller has 5ms latency

http://datasheet.octopart.com/87-5961-211-3M-datasheet-21189...

5 year old Fujitsu FMA1127 had 10ms.

http://www.fujitsu.com/downloads/MICRO/fme/tsc/FMA1127_Data_...

Interrupt latency is measured in nano seconds.

If you had read the PDF, 5ms is the "minimum touch time", which is not latency, but a minimum touch time it can register.

The same software has no problem rendering complex games and doing all kinds of game logic, all in 16.7ms. What makes you think asking for a touch input will take 15 times longer?

Actually its response time.

I already gave you an example of software stack impact on latency - Android sound lag went down from >250ms to respectable 10ms for some Nexus devices. Blame buffers.

> Actually its response time.

Actually, no, it isn't.

"This controller is well known for its < 5.4 milliseconds response time"

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